* {
    padding: 0;
    margin: 0;
    list-style: none;
    text-decoration: none;
  }
  
  .box {
    position: relative;
    margin: 0 auto;
    width: 500px;
    height: 300px;
    user-select: none;
  }
  .box > .img_box img{
    width: 500px;
    height: 300px;
  }
  
  .box > .img_box > ul {
    position: relative;
  }
  .box > .img_box > ul > li {
    position: absolute;
    left:0;
    top: 0;
    display: none;
  }
  /* 激活类名, 显示li */
  .box > .img_box > ul > .imgActive {
    display: block;
  }
  /* 左右箭头 */
  .box > .img_box .arrow_left,
  .box > .img_box .arrow_right {
    font-size: 35px;
    cursor: pointer;
    background-color: #000;
    opacity: 0.4;
    color: #fff;
    width: 40px;
    border-radius: 6px;
    text-align: center;
  }
  
  .box > .img_box .arrow_left:hover,
  .box > .img_box .arrow_right:hover {
    background-color: #000;
    opacity: 0.2;
  }
  
  .box > .img_box .arrow_left {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    left: 0px;
  }
  
  .box > .img_box .arrow_right {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    right: 0px;
  }
  
  /* 小圆点 */
  .box > .bar_box {
    position: absolute;
    bottom: -30px;
    left: 50%;
    transform: translateX(-50%);
  }
  
  .box > .bar_box > ul > li {
    display: inline-block;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    border: 2px solid #000;
    margin: 0 8px;
    cursor: pointer;
    
  }
  
  .box > .bar_box > ul > li:hover {
    background-color: #000;
  }
  .box > .bar_box  .barActive {
    background-color: #000;
  }
  